Water supply system for concrete mixers



y 1942- c. F. BALL 2,282,694

WATER SUPPLY SYSTEM FOR CONCRETE MIXERS Filed Feb. 10. 1941 charm Elia/l6,

Patented May 12, 1942 UNITED STATES PAENT. OFFICE 2,282,694 WATER SUPPLY SYSTEM FOR CONCRETE mans Charles F. Ball, Wauwatosa, Wis., assignor to Chain BeltOompany, Milwaukee, Wis., a corporation of Wisconsin Application February 10, 1941, Serial No. 378,283

6 Claims.

The invention relates to water supply systems for concrete mixers, and more particularly mixers of the type disclosed in prior U. S. Patent No. 2,045,532, granted June 23, 1936 on an application filed by John C. Merwin and myself, wherein a rotatable mixing receptacle is mounted with its axis inclined to the horizontal and has its upper end provided with a material transfer opening and with transfer blades formoving materials therethrough.

In the machine of the said patent the mixing drum or receptacle is provided with the usual interior helical mixing or agitating blades and is rotated in one direction-clockwise as viewed from the rear--for mixing, and in the opposite or counterclockwise direction for discharging. The upper end of the drum is provided with a tubular duct or extension which further elevates the discharge point and. the'said duct is provided with helical blades which prevent direct rearward movement and spilling of the material when the drum is charged to or above its axis but which worm the mixture out when the drum is rotated in the discharge direction. The patent proposed to supply the water necessary for the mixture by a water pipe which discharged into the helical passages formed by the duct blades, or alternatively through a central core member disposed axially within the blades, but in either event the water was discharged to the drum at the inner end of the duct and worked its way by gravity alone into the mass of aggregates and cement in the drum from the exterior of such mass.

It has been found however, that in thistype of machine when the drum is rotated in the mixing direction, with gravity and the helical mixing blades both tending to force the aggregate mass to the lower forward end of the drum, the aggregates-.-which are usually damppi1e or ball up in such forward end with the result that they are carried around by the drum with little or no agitative action which would provide openings in the mass into which the water could find its way. As a consequence in this type of machine, with water admitted only at the rear end, the time required for such water to become thoroughly worked into the mass so as to produce an acceptable mixture is considerably longer than it is in machines in which the drum rotates upon a horizontal axis.

The present invention has for its principal object to provide a water system for concrete mixers, particularly those of the inclined axis type, whereby the time required for the complete working of the water into the mass of aggregates in the drum may be materially. reduced. The present system also lends itself particularly well to the introduction of wash water into the drum, in accordance with the usual practice in the art. With the above and other objects in view which willappear as the description proceeds, the invention comprises the novel details of construction and combinations and arrangements of parts, more fully hereinafter disclosed and particularly pointed out in the-appended claims.

Referring to the accompanying drawing forming a part of this specification in which like reference characters designate like parts in all the views:

Figure 1 is a side elevational view, partly broken awayancl in section, of a concrete mixer unit of the inclined axis truck mounted type, equipped with one form'of water supply system constructed and arranged in accordance with the such as disclosed in my prior applications filed December 6, 1939, Serial No. 307,784, and January 11, 1940, Serial No. 313,323.

In the said drawings the mixing unit is illustrated as comprising a suitable framework It] in which the mixing drum II is journalled for rotation about a longitudinal axis which is inclined to the horizontal, said journalling being provided by rollers I2 at the rear end and by a front bearing, not shown, but common in the art. The drum is arranged to be driven in either direction byan internal combustion engine or other motor mounted within a housing I3 through suitable transmission gearing contained within a housing [4 in the well known manner. The entire unit is illustrated as being mounted upon a chassis l5 of a motor vehicle for movement over the ground, as is also common in the art.

At its elevated rear end the drum is provided with a material transfer duct 16 within which a plurality of helical blades l! are mounted, such blades preferably constituting continuations of pick-up buckets N3 of the type described and claimed in my prior Patent o. 2, 06, granted.

or discharge end of the duct l6.

July 2, 1935. The drum is also provided upon its interior surface with the usual helical mixing blades l9, which when the: drum is rotated in the mixing or clockwise direction as viewed from the rear tend to agitate the aggregates deposited in the drum and move them toward the forward end, and when the drum is rotated in the opposite or counterclockwise direction to move them rearwardly toward the pick-up buckets l8. In the form here shown the perimetral wall of the drum is provided with a charging opening 20, although as above indicated this opening may be omitted and charging may be accomplished through the rear opening provided by the duct I6. This duct, as in the prior Merwin and Ball Patent No. 2,045,532 referred to above, may be provided with an axial core member 2| to which the inner edges of the transfer blades I! may be welded or otherwise rigidly secured.

The water system constituting the present invention comprises a water tank 25 here shown as mounted upon one of the forward frame members II), which tank may in accordance with the usual practice in the art be of the two-compartme'nt type having a'large'compartment for holding the water needed to supply the requirements of the batch of concrete while a smaller compartment may contain water to be used for introduction into the drum after the concrete batch has been discharged for flushing or washing purposes. From the larger compartment a discharge pipe 26 leads to the inlet side of a centrifugal or other power driven pump 21 which may be conveniently operated by power ,derived from the motor within the housing I3. The said discharge pipe 26may be controlled by a suitable valve 28. In like manner the discharge pipe 29 leads from the smaller or wash' water compartment of the tank 25 being controlled by a separate valve 30 and joining the pipe 26 at a T connection 3|.

From the outlet side of the pump 21 the pipe or conduit 32 leads upwardly and thence rearwardly along one of the horizontal frame members ID to the point at the rear of the machine where it is extended diagonally downwards as indicated at 32' and communicates through a suitable slip joint or coupling 33 with a conduit 34 which extends axially of the drum through the core member 2| of the duct 6 and to a point well within the drum where its lower end is or may be provided with a discharge nozzle or protector 35 of the type described and claimed in my prior Patent No. 1,956,521, granted April 24, 1934. The conduit 34 is preferably rigidly secured to the core member 2| and suitable supports 36 brace its inner end from the drum walls, as will be readily apparent from Fig. 1 of the drawing. It therefore follows that the conduit 34 rotates with the drum, such rotation being permitted by reason of the packed joint or coupling 33 referred to above.

The inclined portion 32' of the conduit 32 is provided with a T coupling 40 from which an auxiliary water supply pipe 4| extends in a direction longitudinal of the drum and eccentric to its rotative axis'to a point adjacent the outer This auxiliary conduit may be controlled by a suitable valve 42 and as is clearly shown in both Figs. 1 and 2 the radially innermost portions of the outer ends of the transfer blades I! are notched or recessed as at 43 to clear the end of the pipe 4|. By reason of the helical shape of the blades and the fact that cutaway portions 43 are in their innermost parts radially, the notches need not be of such large dimensions as to materially interfere with the function of the blades in performing their discharge purpose.

As shown in the drawing the axial conduit 34 is preferably of larger diameter than is the auxiliary conduit 4|, in practice it being found that it is preferable that the conduit 34 have a cross sectional area of say three or four times that of the auxiliary conduit, whereby the major portion of the water from the pipe 32 will be introduced into the interior of the mass of ag regates in the drum through the dischar e member 35. Of

course the relative quantity of water discharged duit is so disposed as to discharge its portion of the water at a point adjacent the discharge end of the duct l6 and on the blades l1 and core member 2|, and when the water so discharged is to be used as a portion of that for the concrete batch it finds its way through the helical passages formed between the blades I"! and into the rear portion of the drum where it will encounter the aggregates and cement which have been introduced therein through the charging opening 20 However, the major portion of the water, as above explained, will pass through the larger conduit 34 to the interior of the ag regate mass, and since it is under some pressure imparted by the pump 21 it will more readily be incorporated into the aggregates at the forward end of the drum where the materials tend to pile up above the discharge orifice. Since the conduit 34, as above stated, is secured to and .rotates with the drum and enters the latter through the open rear end, the complicated stuffing boxes which are ordinarily used in conjunction with the front drum bearing to introduce water into drums of the horizontal type are avoided.

It will further be noted from Fig. 2 that due to the inclined portion 32 of the supply pipe 32 45 the auxiliary water from the conduit 4| is discharged into the conduit l6 and onto the blades I! at a point to one side of the vertical median plane of the drum. In this position passage of water from conduit 4| into the drum is greatly facilitated because the blades 1, rotating with the drum in a clockwise direction when viewed from the rear, formconduits for water working down into the drum beneath the mass. Moreover in this position the discharge port of the auxiliary pipe 4| is less likely to be buried or clogged by the concrete as it is discharged from the conduit |6 by the blades l1, since these blades usually complete their discharging function by the time their trailing edges have reached a point between the horizontal and the upper vertical portions of their travel, and any material which might cling to the blades beyond this point tends to slide back through the duct l6 into the drum.

In utilizing the present system for the introduction of wash water thesame procedure is followed except that the water is drawn from the wash water compartment of the tank 25 through the discharge pipe 29 and valve 30 with portions of it being discharged inthe interior of the drum through the protecting member. 35 and lesser portions being discharged through the auxiliary pipe 4| to wash the blades l1, core 2| and conduit walls I B, as will be readily understood.

While one formof the invention has been illustrated and described it is obvious that those skilled in the art may vary the details of construction as well as the precise arrangement of parts without departing from the spirit of the invention and therefore-it is. not wished to be limited to the above disclosureaexcept as may be required by the claims. c

What is claimed is:

1. In a high discharge concrete mixer of the type comprising a mixing receptacle mounted with its axis inclined to the horizontal and having a closed lower end, a material transfer opening at its upper end, and agitating means within it which during the mixing operation tend to force the solid concrete-making materials toward the lower closed end of the receptacle and produce a compacted agitation-resisting mass of such materials; means for facilitating the introduction and. incorporation of the necessary water for the mix into such mass, comprising a main supply conduit extending from exteriorly of the receptacle, through said material transfer opening to a point within the receptacle at which it may discharge water directly within said compacted solids mass; and an auxiliary water supply conduit disposed to discharge water adjacent said transfer opening and exteriorly of said mass.

2. In a high discharge concrete mixer of the type comprising a mixing receptacle mounted with its axis inclined to the horizontal and having a closed lower end, a material transfer opening at its upper end, and agitating means within it which during the mixing operation tend to force the solid concrete-making materials toward the lower closed end of the receptacle and in conjunction with gravitational action produce a compacted relatively dry agitation-resisting mass of such solid materials; means for facilitating the introduction into and distribution throughout such mass of the water necessary for the mix, comprising a main water supply conduit extending from exteriorly of the upper end of the recaptacle, downwardly through said transfer opening and substantially parallel to the inclined axis of the receptacle, to a point well within the latter at which it may discharge water directly within said compacted mass; and an auxiliary water supply conduit disposed to discharge water adjacent to and through said opening into the recaptacle.

3. In a high discharge concrete mixer of the type comprising a mixing receptacle mounted with its axis inclined to the horizontal and having a lower closed end, a material transfer opening at its upper end, and agitating means within it which during the mixing operation force the solid concrete-making materials toward the lower closed end of the receptacle, thereby tending to produce a compacted relatively dry mass of such solid materials in the lower end portion of the receptacle which resists agitation and the incorporation into it of water supplied to its outer surface; means for facilitating the introduction into and distribution throughout such mass of the water necessary for the mix, comprising a conduit for supplying the major portion of such water, extending from exteriorly of the upper end of the receptacle downwardly through said transfer opening to the lower end portion of the recaptacle, where it may discharge said water directly within said compacted mass of solid materials; and a controlled auxiliary conduit disposed to discharge additional water adjacent to and through said transfer-opening for .incorpora-' tion into the mass from the exterior thereof.

4. In a thigh discharge, concrete mixer of the type comprising a rotatable mixing receptacle mounted with its axis inclined to thehorizontal and having a lower closed end, a material transfer openingat its upper end, and agitating means within it which duringthe mixing operation force the solid concrete-making materials toward the lower end of thefireceptacle, thereby tending to produce a compacted ,relatively dry mass {of such solid materials in the lower end portion of the receptacle which resists agitation and the incorporation into it of water supplied to its outer surface; means for facilitating the introduction into and distribution throughout such mass of the water necessary for the mix, comprising a main water supply conduit disposed coaxially of and rotatable with said receptacle and extending from exteriorly of the upper end of the receptacle through said transfer opening to the lower end portion of the receptacle where it may discharge water directly to the interior of said compacted mass of solid materials; and a non-rotatable auxiliary water supply conduit disposed to discharge additional water into said receptacle adjacent to and through said opening, and eccentrically of said axis.

5. In a high discharge concrete mixer of the type comprising a rotatable mixing receptacle mounted with its axis inclined to the horizontal and provided with a lower closed end and a ma terial transfer opening at its upper end, said receptacle also having helical blade means for moving the mixture toward and, through said opening during a discharge operation, and for moving the solid concrete-making materials toward its lower closed end during a mixing operation, which latter movement tends to produce a compacted relatively dry mass of such solid materials in the lower end portion of the receptacle which resists agitation and the incorporation into it of water supplied to its outer surface; means for facilitating the introduction into and distribution throughout such massof the water necessary for the mix, comprising a main water supply conduit extending from exteriorly of the upper end of the receptacle downwardly through said transfer opening to the lower end portion of the receptacle where it may discharge at least a major portion of the required water directly to the interior of said compacted mass of solid materials; and an auxiliary water supply conduit having a port for discharging additional water adjacent to and through said opening into the receptacle, said port being disposed to discharge to one side of the vertical median plane of the receptacle whereby it is materially protected against the completed mixture when the latter is discharged through the opening by the helical blade means.

6. In a high discharge concrete mixer of the type comprising a rotatable mixing receptacle mounted with its axis inclined to the horizontal and provided with a lower closed end and a material transfer opening at its upper end, said receptacle also having helical blade means for moving the mixture toward and through said opening during a discharge operation, and for moving the solid concrete-making materials toward its lower closed end during a mixing operation, which latter movement tends to produce a compacted relatively dry mass of such solid materials in the lower end portion of the receptacle which resists agitation and the incorporation into it of water supplied to its outer surface; means for ;facilitating the introduction into and distribution throughout such mass of the water necessary for the mix, comprising a main water supply conduit extending from exteriorly of the upper end of the receptacle downwardly through said transfer opening to the lower end portion of the receptacle where it may discharge a major portion of the required water directly to the interior of said compacted mass of solid materials; and an auxiliary water supply conduit for discharging additional water 

